The present invention relates generally to communication systems and, in particular, to a method for determining the signal quality of communication resources in a communication system.
Multi-cell communication systems are prevalent today. In such systems, a mobile communication device is provided communication services by fixed communication devices located in the same cell, or coverage area, as the mobile communication device. The cell providing such services at a particular time is known as the serving cell of the mobile communication device. When the signal quality of a mobile communication device""s serving cell becomes unacceptable, a new serving cell is usually selected.
The criteria for when to select a new serving cell and which serving cell to choose, when many are available, vary among communication systems. One approach to serving cell selection requires the mobile communication device to periodically monitor the signal quality of channels in cells with adjacent coverage areas to the serving cell (i.e., neighbor cells). Thus, up-to-date signal quality information is maintained for a list of new serving cell candidates. Such an approach allows a new serving cell to be selected quickly, when, for example, the signal quality of a serving cell suddenly becomes unacceptable.
Typically, mobile communication devices can monitor only one channel at a time. Today, therefore, signal quality measurements of neighbor cell channels are performed when the serving cell is transmitting information designated for other communication devices. If, however, the serving cell is consistently transmitting information designated for the mobile communication device, the mobile communication device has no opportunity to measure the signal quality of neighbor cell channels and maintain up-to-date neighbor cell signal quality information. Thus, new serving cell decisions are either delayed or made using neighbor cell signal quality information that is not current.
Therefore, a need exists for an apparatus and method for determining the signal quality of neighbor cells while receiving information from the serving cell.